1. Feature of The Week

    Nuclear-to-cytoplasmic (N/C) ratio is an effective feature to distinguish cancer cells from their normal counterparts. In conventional cytopathology, cells printed or smeared on a glass slide were stained and then evaluated by two-dimensional (2D) images through light microscopy. A random rayburst sampling (RRBS) framework was developed to detect the nucleus and cell membrane boundaries in three-dimensional (3D) space. Raw images were acquired through a full-field optical coherence tomography (FF-OCT) system with submicron resolution—i.e. 0.8 µm in lateral and 0.9 µm in axial direction. The near isometric resolution enables 3D segmentation of nucleus and cell membrane for determining the volumetric N/C ratio of a single cell. The FF-OCT light source was generated from a laser-diode-pumped crystalline fiber. To achieve high brightness and broadband emissions from 400 nm to 1.6 μm, glass-clad crystal fibers were drawn by the laser-heated pedestal growth and cladded by various glass capillaries. These light sources are eminently suitable for FF-OCT because of their cw operation and near-Gaussian high-brightness spectra. The RRBS framework was insensitive to the selection of seeds and image pixel noise. The robustness of the RRBS framework was verified through the convergence of the N/C ratio searching algorithm. The relative standard deviation of the N/C ratio between different randomly selected seed sets was only 2%. This technique is useful for various in vitro assays on single cell analyses.

    For more information see recent Articles. Courtesy Sheng-Lung Huang from National Taiwan University. To share this article click Here.

  2. Recent Articles From Around The Web

    1. The Frequency Of Focal Choroidal Excavation Detected By Optical Coherence Tomography

      The Frequency Of Focal Choroidal Excavation Detected By Optical Coherence Tomography

      AIM: To determine the frequency and the causes of focal choroidal excavation (FCE) detected by spectral domain optical coherence tomography (SDOCT), and to comment on its clinical importance. MATERIALS AND METHODS: In this study, 632 eyes of the patients with untreated wet age-related macular degeneration (w-AMD, n = 368), central serous chorioretinopathy (CSCR, n = 214), Vogt-Koyanagi-Harada Disease (VKHD, n = 3), adult vitelliform macular dystrophy (AVMD, n = 32), Best vitelliform macular dystrophy (BVMD, n = 2) and other macular dystrophies and specific maculopathies (n = 13) were retrospectively reviewed for the presence of the FCE. Additionally, 228 unaffected fellow eyes without obvious macular pathology ...

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    2. EXAMINATION OF SOL-GEL DERIVED HYDROXYAPATITE ENHANCED WITH SILVER NANOPARTICLES USING OCT AND RAMAN SPECTROSCOPY

      EXAMINATION OF SOL-GEL DERIVED HYDROXYAPATITE ENHANCED WITH SILVER NANOPARTICLES USING OCT AND RAMAN SPECTROSCOPY

      Hydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements of HAp molecular composition and solvent evaporation efficiency the Raman spectroscopy has been chosen. In order to evaluate dispersion and concentration of the silver nanoparticles inside the hydroxyapatite matrix, the optical coherence tomography (OCT) has been ...

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    3. Noninvasive control of influence of polyethylene glycol on transport function of fluorescent colored liposomal nanoparticles

      Noninvasive control of influence of polyethylene glycol on transport function of fluorescent colored liposomal nanoparticles

      The studies were carried out on groups of clinically healthy mice line of outbred CD-1 stock. The model animals were divided into 2 groups and received experimental liposomal formulations. Using the method of fluorescence spectroscopy, we investigated the effectiveness of penetration into the circulatory system of fluorescently stained liposomes with polyethylene glycol (PEG) and without PEG when administered orally. Fluorescence channel with a fiber probe series of multifunctional laser non-invasive diagnostic system “LAKK-M” (SPE “LAZMA” Ltd, Russia) was used as the measuring equipment.

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    4. OCT Based Analysis of RNFL Thickness in Normal Indian Paediatric Population

      OCT Based Analysis of RNFL Thickness in Normal Indian Paediatric Population

      AIM: Cirrus Optical coherence tomography (OCT) provides high resolution cross-sectional images of retina, vitreous and optic nerve head with an axial resolution of 6 μm and a reproducibility of 1.6 μm. There is an availability of integrated normative database only for adult subjects >18 years but the normal reference ranges of (retinal nerve fibre layer) RNFL thickness in paediatric population for comparison is lacking. With this background in mind the present study was undertaken. MATERIALS AND METHODS: 340 eyes of 170 children between 5 to 17 years of age were recruited for study. Full ophthalmic examination was done including ...

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    5. Monte-Carlo simulation of OCT structural images of human skin using experimental B-scans and voxel based approach to optical properties distribution

      Monte-Carlo simulation of OCT structural images of human skin using experimental B-scans and voxel based approach to optical properties distribution

      A method of optical coherence tomography (OCT) structural images reconstruction using Monte Carlo simulations is described. Biological object is considered as a set of 3D elements that allow simulation of media, structure of which cannot be described analytically. Each voxel is characterized by its refractive index and anisotropy parameter, scattering and absorption coefficients. B-scans of the inner structure are used to reconstruct a simulated image instead of analytical representation of the boundary geometry. Henye-Greenstein scattering function, Beer-Lambert-Bouguer law and Fresnel equations are used for photon transport description. Efficiency of the described technique is checked by the comparison of the simulated ...

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    6. Optical Coherence Angiographic Demonstration of Retinal Changes From Chronic Optic Neuropathies

      Optical Coherence Angiographic Demonstration of Retinal Changes From Chronic Optic Neuropathies

      Glaucoma causes a decrease in peripapillary perfused capillary density on optical coherence tomography (OCT) angiography. However, other chronic optic neuropathies have not been explored with OCT angiography to see if these changes were specific to glaucoma. The authors evaluated OCT angiography in 10 patients who suffered various kinds of chronic optic neuropathies, including optic neuritis and ischaemic optic neuropathy, and found that all optic neuropathies showed a decrease in peripapillary vessel density on OCT angiography, regardless of the aetiology of the optic neuropathy. The peripapillary vessel loss on OCT angiography correlated well with the areas of retinal nerve fibre layer ...

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    7. Optical Coherence Tomography Angiography in Macular Edema (Book Chapter)

      Optical Coherence Tomography Angiography in Macular Edema (Book Chapter)

      OCT angiography is a promising new method to visualize the retinal vasculature and choroidal vascular layers in the macular area and provides depth resolved functional information of the blood flow in the vessels. Given that the main moving elements in the eye fundus are contained in vessels, determining a vascular decorrelation signal enables visualization of 3-dimensional retinal and choroidal vascular network without the administration of intravenous dye and thus reducing the risk of potential adverse events.

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    8. Robust phase unwrapping for phase images in Fourier domain Doppler optical coherence tomography

      Robust phase unwrapping for phase images in Fourier domain Doppler optical coherence tomography

      To solve the 2 π 2π phase ambiguity for phase-resolved Doppler images in Doppler optical coherence tomography, we present a modified network programming technique for the first time to the best of our knowledge. The proposed method assumes that error of the discrete derivatives between unwrapped phase image and wrapped phase image can be arbitrary values instead of integer-multiple of 2 π 2π , which makes the real-phase restoration accurate and robust against noise. We compared our proposed method with the network programming method. Parameters including root-mean-square-error and noise amplification degree were adopted for comparison. The experimental study on simulated images, phantom, and ...

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      Mentions: Yong Huang
    9. Optical Coherence Tomography For the Detection of the Vulnerable Plaque

      Optical Coherence Tomography For the Detection of the Vulnerable Plaque

      Morphological characteristics of the atheromatous plaque have been associated with the development of plaque rupture and the pathogenesis of acute coronary syndromes (ACS). Plaques with a specific morphological phenotype that are at high risk of causing ACS are called vulnerable plaques, and can be identified in vivo through the use of intracoronary imaging. Optical coherence tomography (OCT) is a high-resolution intravascular imaging modality that enables detailed visualization of atheromatous plaques. Consequently, OCT is a valuable research tool for examining the role of morphological characteristics of atheromatous plaques in the progression of coronary artery disease and plaque destabilisation, which leads to ...

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    10. Quasi-needle-like focus synthesized by optical coherence tomography

      Quasi-needle-like focus synthesized by optical coherence tomography

      It is known that lateral resolution and depth of focus (DOF) in an optical imaging system are coupled, and a compromise between them has to be made. In this Letter, we propose to resolve the trade-off between lateral resolution and the DOF by a synthetic effective point spread function in optical path length (OPL) domain. A quasi-needle-like focus is synthesized by optical coherence tomography. We demonstrate that the synthesized quasi-needle-like focus provides a four-fold extension of a conventional DOF, while maintaining a high lateral resolution of 2.5 μm over a depth range of approximately 240 μm. The focal range ...

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    11. Choroidal Thickness Variation According to Refractive Error Measured by Spectral Domain-optical Coherence Tomography in Korean Children

      Choroidal Thickness Variation According to Refractive Error Measured by Spectral Domain-optical Coherence Tomography in Korean Children

      Purpose To assess choroidal thickness (CT) variation according to refractive errors using enhanced-depth imaging optical coherence tomography. Methods Eighty-nine eyes (in 89 children) <±6 diopter were categorized into three groups: hyperopia, emmetropia, and myopia, according to refractive error, and underwent choroidal scans using enhanced-depth imaging-optical coherence tomography. CT was measured at the fovea and at 1 mm and 3 mm nasal (N1 and N3), temporal (T1 and T3), superior (S1 and S3), and inferior (I1 and I3) from the fovea. Results Mean foveal CTs were 346.86 µm, 301.97 µm, and 267.46 µm in the hyperopia, emmetropia, and ...

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    12. Interchangeability and reliability of macular perfusion parameter measurements using optical coherence tomography angiography

      Interchangeability and reliability of macular perfusion parameter measurements using optical coherence tomography angiography

      Aim The aim of the study was to investigate the interchangeability and reliability of macular perfusion measurements using optical coherence tomography angiography. Methods A prospective cross-sectional observational study. Healthy adult Chinese subjects were recruited. Macular perfusion parameters were automatically analysed by software included in a spectral-domain optical coherence tomography system. The vessel density (VD) of the whole, parafovea, superior-hemi, inferior-hemi, fovea, temporal, superior, nasal and inferior quadrants as well as the foveal avascular zone (FAZ) and choroidal capillary VD (CCVD) were quantified. Results A total of 51 eyes in 27 subjects were included (8 men and 19 women, mean age ...

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    13. West Nile Virus Chorioretinitis With Foveal Involvement Evolution of Lesions on Optical Coherence Tomography

      West Nile Virus Chorioretinitis With Foveal Involvement Evolution of Lesions on Optical Coherence Tomography

      Purpose: To describe the clinical course of foveal West Nile virus (WNV) chorioretinitis with longitudinal spectral domain optical coherence tomography (SD-OCT) imaging. Methods: Case report. Results: A 41-year-old man with diabetes mellitus presented with flashes and floaters of both eyes (OU) and decreased vision of the right eye (OD) 2 weeks after being discharged from a local hospital. He had been treated for WNV meningoencephalitis, and he recovered systemically with supportive therapy. Ophthalmic examination revealed WNV chorioretinitis bilaterally, with predominantly foveal involvement OD. His best-corrected visual acuity (BCVA) was 8/200 OD and 20/20 of the left eye (OS ...

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    14. QUANTIFICATION OF RETINAL VESSEL TORTUOSITY IN DIABETIC RETINOPATHY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

      QUANTIFICATION OF RETINAL VESSEL TORTUOSITY IN DIABETIC RETINOPATHY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

      Purpose: To investigate the association of vessel tortuosity with severity of diabetic retinopathy (DR) using optical coherence tomography angiography. Methods: We retrospectively analyzed 30 healthy eyes and 121 eyes of diabetic subjects with no DR, mild nonproliferative DR (NPDR), moderate to severe NPDR and proliferative DR (PDR). Binarized images were used to quantify the vessel tortuosity, vessel density, foveal avascular zone (FAZ) area, and FAZ acircularity. The vessels were divided vertically as superficial retinal layer and deep retinal layer, and horizontally as circular areas with 3 mm and 1.5 mm diameters. Analysis of variance was performed for multiple comparisons ...

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    15. SD-OCT Choroidal Thickness in Advanced Primary Open-Angle Glaucoma

      SD-OCT Choroidal Thickness in Advanced Primary Open-Angle Glaucoma

      Purpose: To assess the choroidal thickness in advanced primary open-angle glaucoma (POAG) comparing patients affected by advanced glaucoma and normal subject using spectral domain optical coherence tomography (SD-OCT). Methods: In total, 35 eyes of 35 patients affected by POAG with advanced perimetric defect (mean deviation worse than -12 dB) were prospectively enrolled and underwent a complete ophthalmologic examination, including enhanced depth imaging SD-OCT. One eye of 35 healthy subjects served as control group. Choroidal thickness was measured at the subfoveal location, at 0.5, 1.0, and 2.0 mm nasal and temporal to the fovea. Primary outcome measure was ...

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  5. Picture Gallery

    Near-IR and CP-OCT imaging of suspected occlusal caries lesions Opportunity Research Assistant/Associate in Biophotonics and Endoscopic Imaging at Imperial College London MedLumics Secures 34.4 Million Euros in Series B Funding for OCT Guided Treatment of Atrial Fibrillation Intraoperative 4-Dimensional Microscope-Integrated Optical Coherence TomographyGuided 27-Gauge Transvitreal Choroidal Biopsy for Choroidal Melanoma Handheld optical coherence tomography angiography Intraoperative optical coherence tomography for soft tissue sarcoma differentiation and margin identification In vivo optophysiology reveals that G-protein activation triggers osmotic swelling and increased light scattering of rod photoreceptors Optimization-based adaptive optics for optical coherence tomography (Thesis) 2nd Canterbury Conference on Optical Coherence Tomography (emphasis on broadband optical sources) September 2017 IDx and IBM Watson Health Forge Alliance for Eye Health €4m project to speed diagnosis of esophageal cancer Integrated Local Binary Pattern Texture Features for Classification of Breast Tissue Imaged by Optical Coherence Microscopy
  6. Recent Quotes

    1. While we have been actively advancing our lesion assessment technology for the last two years, we are very pleased to see that the significant Series B investment will give MedLumics the means to complete our best-in-class product, conduct a series of international clinical trials to prove its safety and efficacy, and market it to specialist centers. As the company advances and grows into new areas, we will now expand and develop the team internationally.
      By Eduardo Margallo Balbás
    2. It's the most rapidly adopted ophthalmic technology in history.
      By Joel S. Schuman
    3. Our OCT Angiography congresses is a major force in promoting the transition from FA to OCTA by educating the ophthalmologists .
      By Bruno Lumbroso
    4. The development of OCT in the early 1990s greatly benefited from components and methods used in fiber-optical communications...And still, 25 years later, advances in the optical communications industry continue to greatly benefit OCT.
      By James G. Fujimoto
    5. Research by our group at MIT and our collaborators at Praevium Research and Thorlabs indicated that the coherence length of the VCSEL source was orders of magnitude longer than other swept laser technologies suitable for OCT, which suggested the possibility of long-range OCT imaging.
      By Benjamin M. Potsaid
    6. Our study demonstrates world-record results in cubic meter volume imaging, with at least an order of magnitude larger depth range and volume compared to previous demonstrations of three-dimensional OCT...These results provide a proof-of-principle demonstration for using OCT in this new regime...Long-range OCT is a new range of operation that requires extremely high performance light sources, integrated optical receivers and signal processing.
      By James G. Fujimoto
    7. Research by our group at MIT and our collaborators at Praevium Research and Thorlabs indicated that the coherence length of the VCSEL source was orders of magnitude longer than other swept laser technologies suitable for OCT, which suggested the possibility of long-range OCT imaging.
      By Benjamin M. Potsaid
    8. "The development of OCT in the early 1990s greatly benefited from components and methods used in fiber optical communications,. And still, 25 years later, advances in the optical communications industry continue to greatly benefit OCT.
      By James G. Fujimoto
    9. OCT has revolutionized the treatment of eye disease on a global basis and it is now routinely used to make clinical decisions in treating patients with blinding eye diseases...I’ve been honored to be part of the team that created this technology and to know our creation has improved diagnosis and treatment for millions of eye patients around the world.
      By Carmen A. Puliafito
    10. We believe strongly that our MRO™ sub-dermal fingerprint technology can play a key role in addressing the presentation attack problem by providing an effective deployable solution.
      By Don Bogue